When did they start wearing helments?

Why did the Battle of Cape Matapan happen? What region of the country benefited most from the enormous government spending for the war effort Why? What is the main idea of the Missouri compromise? Who are the Marine Corps pilots that shot down MIG aircraft during Vietnam? How many casualties in the huaynaputina erruption of 1600? Summary of the newcomer by brian patten? What fighting tactic was used on the pacific front? How did the weapons of World War I compare in effectiveness to those used in war today? What sicknesses were caused by World War 1? Popular boardgames played in world war 2? What correlation exits between NATO members and those countries who received money under the Marshall Plan? Why was it difficult to vote for Lincoln in the south? Were was the Vietnam war take place? Around 1794 the British began building a new fort in? Why were the union soldiers called blue bellies? How did children feel in World War 2? What are undesireables from World War 2? What were the battles of Civil War? What were the 4 freedoms in World War 2? What did catapults throw?